Variable gain linear power amplifier and chip

Abstract

The invention discloses a variable gain linear power amplifier and a chip. The variable gain linear power amplifier comprises a variable gain amplifier, and a post-distortion power amplifier, wherein the post-distortion power amplifier comprises a driving stage amplifier and a cascade power stage amplifier, the output end of the variable gain amplifier is connected with the input end of the driving stage amplifier, and the output end of the driving stage amplifier is connected with the input end of the cascade power stage amplifier; and the gain compression distortion characteristics of the driving stage amplifier are compensated according to the gain expansion distortion characteristics of the cascaded power stage amplifier, so that a gain curve of the post-distortion power amplifier obtains a higher 1dB compression point. According to the variable gain linear power amplifier, the gain expansion distortion characteristics generated by the post-stage low-bias class-C amplifier is utilized to compensate the gain compression distortion generated by the pre-stage high-bias class-A amplifier, the improvement of a 1dB compression point is realized under the condition of not introducing an additional predistorter, the additional loss caused by the predistorter is avoided, and the variable gain linear power amplifier can be widely applied to amplifier circuits.

Description

technical field [0001] The invention relates to an amplifier circuit, in particular to a variable gain linear power amplifier and a chip. Background technique [0002] Due to the high frequency of the millimeter wave signal, there is a serious attenuation characteristic in the transmission in the atmosphere, so greater transmission power and efficiency are required to meet the requirements of wireless transmission distance and low power consumption. As a key module in the 5G millimeter wave phased array transmission link, the power amplifier's linear output power determines the upper limit of the transmission power that the transmitter system can achieve and the spectral purity of the transmitted signal. In addition, in order to meet the function of phased array beamforming, the power amplifier also needs to have a wide adjustable range of gain. Therefore, research on variable-gain linear power amplifiers applied to 5G millimeter-wave phased array systems has attracted exte...

AI Technical Summary

Problems solved by technology

However, both of the above two solutions introduce additional reverse distortion modules, which will bring additional loss to the circuit, especially in the millimeter wave band, the parasitic effect of the on-chip circuit is very serious, and the introduction of additional modules will also deteriorate the overall circuit bandwidth, output power and efficiency

For traditional pre-distortion or inter-stage distortion technology, in order to compensate for the attenuation of the distortion device and obtain higher gain, the power stage with a high bias state (such as a class A amplifier) ​​is placed at the end of the circuit and works in a high current state. This will severely limit the efficiency of the circuit

In addition, the introduction of additional modules will increase the complexity of the circuit and increase the chip area, increasing the cost of design and production

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